After adding the dials for representing sensors in a more graphical way, random serial I/O problems occured resulting in incorrect figures being obtained.

The solution was to increase the priority of the serial I/O thread to higher than the rest. By default it inherits the same priority from the calling thread but this isn’t enough.
I started my thead with the QThread::TimeCriticalPriority enumerated type. This seems to have solved the problem. If I discover any more problems, i will attempt setting the whole processor priority higher using the Linux nice command.